Reduce click and wait in the GUI by saving heatmap calculations in .odb

[oharboe]

Description

Calculating heatmaps in the GUI can take a long time for big designs.

Some experimentation to move this calcuation prior to opending the GUI was done.

However, it was concluded that what is really needed is to save such caclulations in the .odb file for the best user experience.

Suggested Solution

Save heatmap calculations done during the build in the .odb file to reduce click+wait in the GUI in the final step. I prefer default on: this is fast for tiny designs and big designs take long anyway, so might as well reduce click+wait in the GUI.

Additional Context

No response

[gadfort]

@oharboe could you provide some details about what heatmaps take a long time? What size bins are you using?
The way the heatmaps are configured it doesn't lend itself to saving the data to the database.

[oharboe]

Test case created from

$ bazel run BoomTile_grt $(pwd)/grt
$ grt/make open_issue

untar and run https://drive.google.com/file/d/1YOnr4QQg4e2gvvHcFpfNB0JxgatEabS3/view?usp=sharing

$ ODB_FILE=results/asap7/BoomTile/base/5_1_grt.odb ./run-me-BoomTile-asap7-base.sh
OpenROAD v2.0-17943-g06a891e4a 
Features included (+) or not (-): +GPU +GUI +Python
This program is licensed under the BSD-3 license. See the LICENSE file for details.
Components of this program may be licensed under more restrictive licenses which must be honored.
GUI_TIMING=1 reading timing, takes a little while for large designs...
No global routing results available, skipping estimate_parasitics
Load .//reports/asap7/BoomTile/base/congestion.rpt for details
Populating timing paths...OK
openroad> gui::show

30 seconds in this case, cases I can't share can take longer: